This invention relates to a composite laminate, and more particularly to a composite laminate for the vibration damping which has excellent vibration damping performance, particularly at high temperatures.
Heretofore, in order to inhibit or prevent the noise or vibration generated from a variety of mechanical and electrical devices, structures and the like, there have been proposed or commercially used composite laminates for the vibration damping wherein as a vibration damper, a resin or resin composition having viscoelasticity is interposed between substrates such as metal plates, and wherein the internal friction due to the shearing deformation of the vibration damper described above is utilized to improve the vibration damping performance.
Known resins for a vibration damper in such a composite laminate are polyethylene and polypropylene which are representative thermoplastic resins. Further, Japanese Patent Laid-Open Pub. Nos. 43251/1979 and 43252/1979 disclose compositions for a vibration damper containing polyisobutylene as a main component, dienic hydrocarbon polymers or cyclic olefinic polymers, and inorganic fillers. Furthermore, Japanese Patent Laid-Open Pub. No. 34949/1982 describes a composite laminate wherein a vibration damper comprising an ethylene-vinyl acetate copolymer is hot-pressed between steel plates. Moreover, Japanese Patent Publication No. 12451/1964 teaches a polymer composition for a vibration damper wherein the polymer composition comprises a heterogeneous amorphous copolymer of ethylene or straight chain .alpha.-olefins containing from 3 to 10 carbon atoms and acrylic acid or methacrylic acid.
However, the composite laminates using such prior art vibration dampers are insufficient in its vibration damping performance. Particularly, the vibration damping performance at a high temperature of at least 80.degree. C. is inferior. Accordingly, it is not preferable to use the prior art composite laminates as, for example, a composite laminate for the vibration damping at high temperatures, at the periphery of high temperature members such as engines.